pf2e.fyi
From Pathfinder Society Scenario #6-11: The Godsrain and the Dragon, which isn't enabled.

Tempestuous Koi Egg

COMPLEX HAZARD 9
Stealth +24 (expert)
Description A raging storm covers the mountain lake as spring water levitates from the lake to fall back down in a driving spiral of steaming rain. In the depths of the storm, barely visible, is a tiny koi egg surrounded by three bands of water.

Disable DC 29 Arcana, DC 29 Religion, DC 29 Nature, or DC 29 Occultism to purify the magic corrupting the ascension ritual, or DC 32 Diplomacy or DC 32 Performance to soothe the spirit within the koi egg and give it the strength to fight off the corruption itself; four total successes are required to purify the ritual, each of the first three successes purifying one ring of water and the final one halting the ritual itself. If the cursed comb has not been removed from the ritual site, then succeeding on this final check merely halts the ritual; if the cursed comb has been removed from the ritual site, then succeeding on this final check completes the ascension ritual.

AC 10; Fort +10, Will +10
HP 1 (BT 0)

Immune to All Damage (Until Final Ring is Purified)
Raise the Storm
Trigger Xalreonshin rolls initiative, three rounds pass after the PCs begin speaking with Xalreonshin, or a creature other than Xalreonshin comes within 40 feet of the egg

Effect The turbulent koi egg churns the lake surface, ejecting water into the sky. A 1-mile-radius area centered on the egg becomes filled with heavy rain and strong wind imposing a -2 circumstance penalty to Perception checks and requiring flying creatures to Maneuver in Flight.
Routine (1 action) Torrential water descends from the sky, taking the shape of a dragon that smashes into one creature within 60 feet of the egg. The dragon always targets the creature that is closest to the egg, dealing 2d12 bludgeoning damage and 2d12 fire damage in a spray of boiling water (DC 28 Fortitude save). Creatures that fail the save are pushed 10 feet away. Creatures that have the earth trait, are carrying an item with the earth trait, or are otherwise strongly tied to elemental earth (such as an earth elemental sorcerer or kineticist) get the result one degree of success better than the outcome of their save, as the power of elemental earth overcomes water.
Reset The turbulent koi egg can attempt to hatch again, restarting the ascension ritual, after 1000 years of Xalreonshin's care.
Pathfinder Society Scenario #6-11: The Godsrain and the DragonORC